<script setup lang="ts">
import { deleteCartListApi, getCartListApi, updateSeletedApi, updateSkuNumberApi } from '@/api/cart';
import type { InputNumberBoxEvent } from '@/components/vk-data-input-number-box/vk-data-input-number-box';
import { useMemberStore } from '@/stores';
import type { CartItem } from '@/types/cart';
import { onShow } from '@dcloudio/uni-app';
import { computed } from 'vue';
import { ref } from 'vue';
import {useGuessList} from '@/composables/index'
// 节流函数
type ThrottleFunction = (...args: any[]) => void;

function throttle(func: ThrottleFunction, delay: number): ThrottleFunction {
  let timer: null | number = null;
  let lastTime = 0;
  return function(this:any, ...args: any[]) {
    const now = new Date().getTime();
    if (now - lastTime < delay) {
      clearTimeout(timer as number);
      timer = setTimeout(() => {
        func.apply(this, args);
      }, delay);
    } else {
      lastTime = now;
      func.apply(this, args);
    }
  };
}

const memberStore = useMemberStore()
const cartList = ref<CartItem[]>([])
// 获取购物车列表页数据
const getCartListData = async ()=>{
  const res = await getCartListApi()
  cartList.value = res.result
}
// 购物车列表页滑动删除功能
const handleDelete = (skuId: string)=>{
  uni.showModal({
    content: '是否确认删除？',
    success:async (res)=>{
      if(res.confirm){
        await deleteCartListApi({ids: [skuId]})
        // 重新加载购物车列表页数据
        await getCartListData()
      }
    },
  })
}
// 步进器（单品数量加减）的change事件
const handleChange = throttle( (ev: InputNumberBoxEvent)=>{
   updateSkuNumberApi(ev.index, {count: ev.value})
}, 1000)

// sku选中事件
const handleChangeSelected = (item: CartItem)=>{
  item.selected = !item.selected
  updateSkuNumberApi(item.skuId, {selected: item.selected})
}

// 计算全选状态
const isSelectedAll = computed(()=>{
  return cartList.value.length && cartList.value.every(item=>item.selected)
})

// 全选按钮事件
const handleSelectAll = async ()=>{
  const _isSelectedAll = !isSelectedAll.value
  cartList.value.forEach(item=>{
    item.selected = _isSelectedAll
  })
  // 调用接口，更新后端的全选状态
  await updateSeletedApi({selected: _isSelectedAll})
}

// 计算属性获取哪个单品处于被选中状态
const selectedCartList = computed(()=>{
  return cartList.value.filter(item=>item.selected)
})

// 计算属性计算所有被选中单品的总件数
const selectedCartListTotal = computed(()=>{
  return selectedCartList.value.reduce((sum, item)=>sum+item.count, 0)
})

// 计算属性计算所有单品的总金额
const selectedCartListMoney = computed(()=>{
  return selectedCartList.value.reduce((sum, item)=>sum+item.count * item.nowPrice, 0).toFixed(2)
})

// 去结算按钮事件
const toPay = ()=>{
  if(selectedCartListTotal.value === 0){
    return uni.showToast({
      icon: 'none',
      title: '请添加商品！'
    })
  }else{
    uni.navigateTo({
      url:'/pagesOrder/create/create',
    })
  }
}
// 触底加载更多猜你喜欢数据
// 通过封装的组合式函数引入
const {guessRef, onScrolltolower} = useGuessList()
onShow(()=>{
  console.log('onshow')
  // 登录情况下才能加载购物车数据
  if(memberStore.profile){
    getCartListData()
  }
})
</script>

<template>
  <scroll-view scroll-y class="scroll-view"  @scrolltolower="onScrolltolower" >
    <!-- 已登录: 显示购物车 -->
    <template v-if="memberStore.profile">
      <!-- 购物车列表 -->
      <view class="cart-list" v-if="cartList.length">
        <!-- 优惠提示 -->
        <view class="tips">
          <text class="label">满减</text>
          <text class="desc">满1件, 即可享受9折优惠</text>
        </view>
        <!-- 滑动操作分区 -->
        <uni-swipe-action>
          <!-- 滑动操作项 -->
          <uni-swipe-action-item v-for="item in cartList" :key="item.skuId" class="cart-swipe">
            <!-- 商品信息 -->
            <view class="goods">
              <!-- 选中状态 -->
              <text @tap="handleChangeSelected(item)" class="checkbox" :class="{ checked: item.selected }"></text>
              <navigator
                :url="`/pages/goods/goods?id=${item.id}`"
                hover-class="none"
                class="navigator"
              >
                <image
                  mode="aspectFill"
                  class="picture"
                  :src="item.picture"
                ></image>
                <view class="meta">
                  <view class="name ellipsis">{{item.name}}</view>
                  <view class="attrsText ellipsis">{{item.attrsText}}</view>
                  <view class="price">{{item.nowPrice}}</view>
                </view>
              </navigator>
              <!-- 商品数量 -->
              <view class="count">
                <vk-data-input-number-box 
                  v-model="item.count"
                  :min="1"
                  :max="item.stock"
                  :index="item.skuId"
                  @change="handleChange"/>
              </view>
            </view>
            <!-- 右侧删除按钮 -->
            <template #right>
              <view class="cart-swipe-right">
                <button class="button delete-button" @tap="handleDelete(item.skuId)">删除</button>
              </view>
            </template>
          </uni-swipe-action-item>
        </uni-swipe-action>
      </view>
      <!-- 购物车空状态 -->
      <view class="cart-blank" v-else>
        <image src="/static/images/blank_cart.png" class="image" />
        <text class="text">购物车还是空的，快来挑选好货吧</text>
        <navigator open-type="switchTab" url="/pages/index/index" hover-class="none">
          <button class="button">去首页看看</button>
        </navigator>
      </view>
      <!-- 吸底工具栏 -->
      <view class="toolbar">
        <text class="all" :class="{ checked: isSelectedAll }" @tap="handleSelectAll">全选</text>
        <text class="text">合计:</text>
        <text class="amount">{{selectedCartListMoney}}</text>
        <view class="button-grounp">
          <view class="button payment-button" :class="{ disabled: selectedCartList.length === 0 }" @tap="toPay"> 去结算({{selectedCartListTotal}}) </view>
        </view>
      </view>
    </template>
    <!-- 未登录: 提示登录 -->
    <view class="login-blank" v-else>
      <text class="text">登录后可查看购物车中的商品</text>
      <navigator url="/pages/login/login" hover-class="none">
        <button class="button">去登录</button>
      </navigator>
    </view>
    <!-- 猜你喜欢 -->
    <FnGuess ref="guessRef"></FnGuess>
    <!-- 底部占位空盒子 -->
    <view class="toolbar-height"></view>
  </scroll-view>
</template>

<style lang="scss">
// 根元素
:host {
  height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background-color: #f7f7f8;
}

// 滚动容器
.scroll-view {
  flex: 1;
  overflow-y: scroll;
}

// 购物车列表
.cart-list {
  padding: 0 20rpx;

  // 优惠提示
  .tips {
    display: flex;
    align-items: center;
    line-height: 1;
    margin: 30rpx 10rpx;
    font-size: 26rpx;
    color: #666;

    .label {
      color: #fff;
      padding: 7rpx 15rpx 5rpx;
      border-radius: 4rpx;
      font-size: 24rpx;
      background-color: #db1818;
      margin-right: 10rpx;
    }
  }

  // 购物车商品
  .goods {
    display: flex;
    padding: 20rpx 20rpx 20rpx 80rpx;
    border-radius: 10rpx;
    background-color: #fff;
    position: relative;

    .navigator {
      display: flex;
    }

    .checkbox {
      position: absolute;
      top: 0;
      left: 0;

      display: flex;
      align-items: center;
      justify-content: center;
      width: 80rpx;
      height: 100%;

      &::before {
        content: '\e6cd';
        font-family: 'erabbit' !important;
        font-size: 40rpx;
        color: #444;
      }

      &.checked::before {
        content: '\e6cc';
        color: #db1818;
      }
    }

    .picture {
      width: 170rpx;
      height: 170rpx;
    }

    .meta {
      flex: 1;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      margin-left: 20rpx;
    }

    .name {
      height: 72rpx;
      font-size: 26rpx;
      color: #444;
    }

    .attrsText {
      line-height: 1.5;
      padding: 0 15rpx;
      font-size: 24rpx;
      align-self: flex-start;
      border-radius: 4rpx;
      color: #888;
      background-color: #f7f7f8;
    }

    .price {
      line-height: 1;
      font-size: 26rpx;
      color: #444;
      margin-bottom: 2rpx;
      color: #cf4444;

      &::before {
        content: '￥';
        font-size: 80%;
      }
    }

    // 商品数量
    .count {
      position: absolute;
      bottom: 10rpx;
      right: 5rpx;

      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 220rpx;
      height: 48rpx;

      .text {
        height: 100%;
        padding: 0 20rpx;
        font-size: 32rpx;
        color: #444;
      }

      .input {
        height: 100%;
        text-align: center;
        border-radius: 4rpx;
        font-size: 24rpx;
        color: #444;
        background-color: #f6f6f6;
      }
    }
  }

  .cart-swipe {
    display: block;
    margin: 20rpx 0;
  }

  .cart-swipe-right {
    display: flex;
    height: 100%;

    .button {
      display: flex;
      justify-content: center;
      align-items: center;
      width: 50px;
      padding: 6px;
      line-height: 1.5;
      color: #fff;
      font-size: 26rpx;
      border-radius: 0;
    }

    .delete-button {
      background-color: #cf4444;
    }
  }
}

// 空状态
.cart-blank,
.login-blank {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  height: 60vh;
  .image {
    width: 400rpx;
    height: 281rpx;
  }
  .text {
    color: #444;
    font-size: 26rpx;
    margin: 20rpx 0;
  }
  .button {
    width: 240rpx !important;
    height: 60rpx;
    line-height: 60rpx;
    margin-top: 20rpx;
    font-size: 26rpx;
    border-radius: 60rpx;
    color: #fff;
    background-color: #db1818;
  }
}

// 吸底工具栏
.toolbar {
  position: fixed;
  left: 0;
  right: 0;
  bottom: var(--window-bottom);
  z-index: 1;

  height: 100rpx;
  padding: 0 20rpx;
  display: flex;
  align-items: center;
  border-top: 1rpx solid #ededed;
  border-bottom: 1rpx solid #ededed;
  background-color: #fff;
  box-sizing: content-box;

  .all {
    margin-left: 25rpx;
    font-size: 14px;
    color: #444;
    display: flex;
    align-items: center;
  }

  .all::before {
    font-family: 'erabbit' !important;
    content: '\e6cd';
    font-size: 40rpx;
    margin-right: 8rpx;
  }

  .checked::before {
    content: '\e6cc';
    color: #db1818;
  }

  .text {
    margin-right: 8rpx;
    margin-left: 32rpx;
    color: #444;
    font-size: 14px;
  }

  .amount {
    font-size: 20px;
    color: #cf4444;

    .decimal {
      font-size: 12px;
    }

    &::before {
      content: '￥';
      font-size: 12px;
    }
  }

  .button-grounp {
    margin-left: auto;
    display: flex;
    justify-content: space-between;
    text-align: center;
    line-height: 72rpx;
    font-size: 13px;
    color: #fff;

    .button {
      width: 240rpx;
      margin: 0 10rpx;
      border-radius: 72rpx;
    }

    .payment-button {
      background-color: #db1818;

      &.disabled {
        opacity: 0.6;
      }
    }
  }
}
// 底部占位空盒子
.toolbar-height {
  height: 100rpx;
}
</style>